In order to maximize efficiency of limited radio resources, an effective transmission and reception scheme and various methods of utilization thereof have been proposed in a broadband wireless communication system. A carrier aggregation system is one of systems considered in a next-generation wireless communication system. The carrier aggregation system implies a system which supports a broadband by aggregating one or more carriers having a bandwidth narrower than that of a desired broadband when a wireless communication system intends to support the broadband.
A wireless communication system such as conventional 3rd generation partnership project (3GPP) long term evolution (LTE) uses a carrier of various bandwidths, but is a single-carrier system which uses one carrier. Meanwhile, a next-generation wireless communication system such as LTE-advanced (A) may be a carrier aggregation system which aggregates multiple carriers, that is, which uses carrier aggregation.
The carrier aggregation uses a plurality of component carriers (CCs). The CC is defined with a center frequency and a bandwidth. One downlink (DL) CC or a pair of an uplink (UL) CC and a DL CC is mapped to one cell. When a user equipment receives a service by using a plurality of DL CCs, it can be said that the user equipment receives the service from a plurality of serving cells.
A carrier aggregation system can operate based on frequency division duplex (FDD) or time division duplex (TDD). In the FDD, UL transmission and DL transmission are achieved using different frequency resources. In the TDD, UL transmission and DL transmission are achieved at different times.
It is assumed that each cell uses the same UL-DL configuration when the conventional carrier aggregation system operates based on the TDD. Herein, the DL-UL configuration implies a configuration in which each subframe in a radio frame consists of a UL subframe, a DL subframe, or a special subframe. However, the DL-UL configuration can be set differently for each cell when a future carrier aggregation system operates based on the TDD. Therefore, it may be necessary to modify a method of transmitting and receiving a signal of a user equipment which assumes that each cell has the same DL-UL configuration.